With recent development of wireless communication techniques, diverse ear-sets for wireless communication with audio-source devices are under development. Most latest developing ear-sets uses Bluetooth technique to be wirelessly connected with diverse types of audio source devices (e.g., a television, a smart phone, a navigation device for vehicles and the like) for communication and to wirelessly receive and output an audio signal.
However, a conventional ear-set has a disadvantage that a user with poor hearing is unable to use, because of no specifications for every user, and another disadvantage that a user might feel uncomfortable in use, because of no remote controller for controlling it together with conventional audio-source devices. In addition, when try to recognize external sounds in wearing the conventional ear-set, a user has to remove the ear-set from the ear or adjust an ear-set output volume with the hand inconveniently. Under such environments where the manual adjustment is not easy (e.g., bike-riding, jogging and the like), the conventional ear-set has a further disadvantage of dangerous accidents with the slightest provocation.